criticalCVSS 9.8Vulnerability

GHSA-2689-5p89-6j3j

`uefi-firmware` contains a stack out-of-bounds write vulnerability in the native tiano/EFI decompressor. in `uefi_firmware/compression/Tiano/Decompress.c`, `MakeTable()` does not validate that bit-length values read from the compressed bitstream are within the expected range (`0..16`). a crafted firmware blob can supply bit lengths greater than `16`, causing out-of-bounds writes to the stack-allocated `Count[17]` array and related decode tables. reachability is through the normal parsing path: `CompressedSection.process()` -> `efi_compressor.TianoDecompress()` -> `TianoDecompress()` -> `ReadPTLen()` -> `MakeTable()`. Minimum impact is a deterministic crash; depending on build/runtime details, the stack memory corruption may be exploitable for code execution in the context of the parsing process. this project shipped its own copy of the decompressor without the upstream EDK2 hardening for this bug class. References: - PR: <https://github.com/theopolis/uefi-firmware-parser/pull/145> - fix commit: <https://github.com/theopolis/uefi-firmware-parser/commit/bf3dfaa8a05675bae6ea0cbfa082ddcebfcde23e> - upstream related fixes: CVE-2017-5731, CVE-2017-5732, CVE-2017-5733, CVE-2017-5734, CVE-2017-5735

Properties

ghsa_id
GHSA-2689-5p89-6j3j
severity
critical
summary
UEFI Firmware Parser has a stack out-of-bounds write in tiano decompressor MakeTable
cvss_score
9.8
cve_id
GHSA-2689-5p89-6j3j
cvss_vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
is_ghsa_only
true
ghsa_published
2026-04-16T01:30:48Z
source_url
https://github.com/advisories/GHSA-2689-5p89-6j3j
ghsa_updated
2026-04-16T01:30:49Z

Related Entities (4)

AFFECTS (1)

[Software]pip/uefi-firmware

HAS_WEAKNESS (1)

[Weakness]Out-of-bounds Write

REPORTED_BY (1)

[Source]GitHub Advisory Database

VULNERABLE_TO (1)

[Software]pip/uefi-firmware

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GHSA-2689-5p89-6j3j (CVSS 9.8) — Ninja Signal Threat Intelligence | Ninja Signal